Develop Reference

SnapStart function priming - Doesn't seem to be working

I’m somewhat new to Kotlin/Java, but I have been using AWS Lambda for several years now (all Python and Node). I’ve been trying to “successfully” enable SnapStart on a SpringBoot Lambda using Kotlin running on java11 corretto (the only runtime supported currently), but it doesn’t seem to be working as I would have expected.
I have hooked into the CRaC lifecycle methods beforeCheckpoint and afterRestore. In beforeCheckpoint I’ve initialized the SpringBoot application and I can see it in the deployment logs (AWS creates log streams for the deployment phase with SnapStart lambdas).
However, the concerning thing is I’m also seeing the SpringBoot app get initialized in the function invocation logs too. I would have expected that to only happen during the deployment/initialization phase when the snapshot is being created. As a result I’m not really seeing a tremendous improvement on latency or overall.
Any ideas why this is happening?

I ran into essentially the same issue (with Java instead of Kotlin) and the solution was to switch the runtime->handler from
org.springframework.cloud.function.adapter.aws.SpringBootStreamHandler
to
org.springframework.cloud.function.adapter.aws.FunctionInvoker::handleRequest

It would probably be worth mentioning that as of 2023-02-20 SnapStart isn't engaged for $LATEST version of an AWS Lambda function, i.e. make sure you are invoking a particular published version. Otherwise, Best practices for working with Lambda SnapStart article says that the main performance killers are dynamically loaded classes, and network connections that need to be re-established from time to time.
From Snapstart Integration issue raised for Spring Cloud Function on GitHub I tend to think that switching to org.springframework.cloud.function.adapter.aws.FunctionInvoker probably somewhat helps, but doesn't address the performance challenges mentioned above. I'm not sure if I'm interpreting olegz's advice correctly, but what worked best so far for my AWS lambda function built with Spring Boot/Spring Cloud Function is a "warm-up" config. It hooks into the CRaC lifecycle via beforeCheckpoint() and issues dummy requests to S3 and DynamoDB before the VM snapshot is made. This way most dynamically-loaded classes are pre-loaded, and network connections are pre-established, before any subsequent function invocation takes place.
package eu.mycompany.mysamplesystem.attachmentstore.configuration;
import com.amazonaws.services.lambda.runtime.events.S3Event;
import eu.mycompany.mysamplesystem.attachmentstore.handlers.MainEventHandler;
import lombok.extern.slf4j.Slf4j;
import org.crac.Core;
import org.crac.Resource;
import org.springframework.context.annotation.Configuration;
import software.amazon.awssdk.services.s3.model.NoSuchKeyException;
import java.util.ArrayList;
import java.util.List;
#Configuration
#Slf4j
public class WarmUpConfig implements Resource {
private final MainEventHandler mainEventHandler;
public WarmUpConfig(final MainEventHandler mainEventHandler) {
Core.getGlobalContext().register(this);
this.mainEventHandler = mainEventHandler;
}
#Override
public void beforeCheckpoint(org.crac.Context<? extends Resource> context) {
log.debug("Warm-up MainEventHandler by issuing dummy requests");
dummyS3Invocation();
dummyDynamoDbInvocation();
}
#Override
public void afterRestore(org.crac.Context<? extends Resource> context) {
}
public void dummyS3Invocation() {
S3Event s3Event = generateWarmUpEvent("ObjectCreated:Put");
try {
mainEventHandler.handleRequest(s3Event, null);
throw new IllegalStateException("Warm-up event processing should have reached S3 and failed with S3Exception");
} catch (NoSuchKeyException e) {
log.debug("S3Exception is expected, since it is a warm-up");
}
}
public void dummyDynamoDbInvocation() {
S3Event s3Event = generateWarmUpEvent("ObjectRemoved:Delete");
mainEventHandler.handleRequest(s3Event, null);
}
private S3Event generateWarmUpEvent(String eventName) {
S3Event.S3BucketEntity s3BucketEntity = new S3Event.S3BucketEntity("hopefully_non_existing_bucket", null, null);
S3Event.S3ObjectEntity s3ObjectEntity = new S3Event.S3ObjectEntity("hopefully/non/existing.key", 0L, null, null, null);
S3Event.S3Entity s3Entity = new S3Event.S3Entity(null, s3BucketEntity, s3ObjectEntity, null);
List<S3Event.S3EventNotificationRecord> records = new ArrayList<>();
records.add(new S3Event.S3EventNotificationRecord(null, eventName, null, null, null, null, null, s3Entity, null));
return new S3Event(records);
}
}
P.S.: The MainEventHandler is basically the entry point to all the business logic exposed by the Function.
#SpringBootApplication
#RequiredArgsConstructor
public class Lambda {
private final MainEventHandler mainEventHandler;
public static void main(String... args) {
SpringApplication.run(Lambda.class, args);
}
#Bean
public Function<Message<S3Event>, String> defaultFunctionLambda() {
return message -> {
Context context = message.getHeaders().get("aws-context", Context.class);
return mainEventHandler.handleRequest(message.getPayload(), context);
};
}
}

java.lang.IllegalAccessError: tried to access method net.sourceforge.tess4j.Tesseract.<init>()V from class Tess4jTest.TestTess

I did a Java OCR project with Tesseract in the Mirth.When I run the jar file from the Mirth,I get this error.When I search it,I found that there is a init() method and also it is a protected void in Tesseract.java.I think that maybe it is the reason for that error.
What should I do?Thank you so much for your helps.
package Tess4jTest;
import java.io.File;
import java.io.IOException;
import net.sourceforge.tess4j.*;
public class TestTess {
public static String Tc;
public static String phone;
public static String date;
public static void main(String[] args) {
//System.out.println(returnText("C:\\Users\\Nevzat\\Desktop\\deneme.pdf"));
}
public static String returnText(String fileName){
File imageFile = new File(fileName);
if(imageFile.exists()){
Tesseract instance = new Tesseract();
instance.setDatapath("C:\\imageRAD\\Onam\\tessdata");
String result = null;
try {
result = instance.doOCR(imageFile);
} catch (TesseractException e) {
System.err.println(e.getMessage());
}
if(result!=null){
int i=result.indexOf("Numarasn: ");
int j=result.indexOf("Tel No:");
int k=result.indexOf("Bilgllendirme Tarihl:");
Tc = result.substring(i+10, i+21);
phone = result.substring(j+8,j+23);
date = result.substring(k+22,k+32);
//System.out.println(result);
}else{
return "Null Error!";
}
}else{
return "Does not found a file!";
}
return Tc+","+phone+","+date;
}
public static String returnTC() throws IOException{
return Tc;
}
public static String returnPhone() throws IOException{
return phone;
}
public static String returnDate() throws IOException{
return date;
}
}

The error you got occurs when you try to create an object with a private constructor. (<init>() is the name of a constructor with no parameters)
Looking at the tess4j source I found a method with the following documentation:
#deprecated As of Release 2.0, use default constructor instead.
Looking at the source before 2.0 reveals the default constructor was private.
This means your problem is most likely that you are compiling against a version newer than 2.0, but your environment is running one older than 2.0.
Either update your environment or downgrade the library you build against to fix it.

I solved the error and have finished the project.I mention step by step
1.You have to use right jar files for tess4j.
2.Add java project all of in the tess4j-3.2.1.zip except tess4j-3.2.1.jar via Build Path.
3.Add tess4j-1.5.jar from this
4.Add tessdata folder,ghost4j-0.5.1.jar,jna-4.1.jar,tess4j.jar and jar file of your java project.

Programmatic SchemaExport / SchemaUpdate with Hibernate 5 and Spring 4

With Spring 4 and Hibernate 4, I was able to use Reflection to get the Hibernate Configuration object from the current environment, using this code:
#Autowired LocalContainerEntityManagerFactoryBean lcemfb;
EntityManagerFactoryImpl emf = (EntityManagerFactoryImpl) lcemfb.getNativeEntityManagerFactory();
SessionFactoryImpl sf = emf.getSessionFactory();
SessionFactoryServiceRegistryImpl serviceRegistry = (SessionFactoryServiceRegistryImpl) sf.getServiceRegistry();
Configuration cfg = null;
try {
Field field = SessionFactoryServiceRegistryImpl.class.getDeclaredField("configuration");
field.setAccessible(true);
cfg = (Configuration) field.get(serviceRegistry);
} catch (NoSuchFieldException | SecurityException | IllegalArgumentException | IllegalAccessException e) {
e.printStackTrace();
}
SchemaUpdate update = new SchemaUpdate(serviceRegistry, cfg);
With Hibernate 5, I must use some MetadataImplementor, which doesn't seems to be available from any of those objects. I also tried to use MetadataSources with the serviceRegistry. But it did say that it's the wrong kind of ServiceRegistry.
Is there any other way to get this working?

Basic idea for this problem is:
implementation of org.hibernate.integrator.spi.Integrator which stores required data to some holder. Register implementation as a service and use it where you need.
Work example you can find here https://github.com/valery-barysok/spring4-hibernate5-stackoverflow-34612019
create org.hibernate.integrator.api.integrator.Integrator class
import hello.HibernateInfoHolder;
import org.hibernate.boot.Metadata;
import org.hibernate.engine.spi.SessionFactoryImplementor;
import org.hibernate.service.spi.SessionFactoryServiceRegistry;
public class Integrator implements org.hibernate.integrator.spi.Integrator {
#Override
public void integrate(Metadata metadata, SessionFactoryImplementor sessionFactory, SessionFactoryServiceRegistry serviceRegistry) {
HibernateInfoHolder.setMetadata(metadata);
HibernateInfoHolder.setSessionFactory(sessionFactory);
HibernateInfoHolder.setServiceRegistry(serviceRegistry);
}
#Override
public void disintegrate(SessionFactoryImplementor sessionFactory, SessionFactoryServiceRegistry serviceRegistry) {
}
}
create META-INF/services/org.hibernate.integrator.spi.Integrator file
org.hibernate.integrator.api.integrator.Integrator
import org.hibernate.boot.spi.MetadataImplementor;
import org.hibernate.tool.hbm2ddl.SchemaExport;
import org.hibernate.tool.hbm2ddl.SchemaUpdate;
import org.springframework.boot.CommandLineRunner;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
#SpringBootApplication
public class Application implements CommandLineRunner {
public static void main(String[] args) {
SpringApplication.run(Application.class, args);
}
#Override
public void run(String... args) throws Exception {
new SchemaExport((MetadataImplementor) HibernateInfoHolder.getMetadata()).create(true, true);
new SchemaUpdate(HibernateInfoHolder.getServiceRegistry(), (MetadataImplementor) HibernateInfoHolder.getMetadata()).execute(true, true);
}
}

I would like to add up on Aviad's answer to make it complete as per OP's request.
The internals:
In order to get an instance of MetadataImplementor, the workaround is to register an instance of SessionFactoryBuilderFactory through Java's ServiceLoader facility. This registered service's getSessionFactoryBuilder method is then invoked by MetadataImplementor with an instance of itself, when hibernate is bootstrapped. The code references are below:
Service Loading
Invocation of getSessionFactoryBuilder
So, ultimately to get an instance of MetadataImplementor, you have to implement SessionFactoryBuilderFactory and register so ServiceLoader can recognize this service:
An implementation of SessionFactoryBuilderFactory:
public class MetadataProvider implements SessionFactoryBuilderFactory {
private static MetadataImplementor metadata;
#Override
public SessionFactoryBuilder getSessionFactoryBuilder(MetadataImplementor metadata, SessionFactoryBuilderImplementor defaultBuilder) {
this.metadata = metadata;
return defaultBuilder; //Just return the one provided in the argument itself. All we care about is the metadata :)
}
public static MetadataImplementor getMetadata() {
return metadata;
}
}
In order to register the above, create simple text file in the following path(assuming it's a maven project, ultimately we need the 'META-INF' folder to be available in the classpath):
src/main/resources/META-INF/services/org.hibernate.boot.spi.SessionFactoryBuilderFactory
And the content of the text file should be a single line(can even be multiple lines if you need to register multiple instances) stating the fully qualified class path of your implementation of SessionFactoryBuilderFactory. For example, for the above class, if your package name is 'com.yourcompany.prj', the following should be the content of the file.
com.yourcompany.prj.MetadataProvider
And that's it, if you run your application, spring app or standalone hibernate, you will have an instance of MetadataImplementor available through a static method once hibernate is bootstraped.
Update 1:
There is no way it can be injected via Spring. I digged into Hibernate's source code and the metadata object is not stored anywhere in SessionFactory(which is what we get from Spring). So, it's not possible to inject it. But there are two options if you want it in Spring's way:
Extend existing classes and customize all the way from
LocalSessionFactoryBean -> MetadataSources -> MetadataBuilder
LocalSessionFactoryBean is what you configure in Spring and it has an object of MetadataSources. MetadataSources creates MetadataBuilder which in turn creates MetadataImplementor. All the above operations don't store anything, they just create object on the fly and return. If you want to have an instance of MetaData, you should extend and modify the above classes so that they store a local copy of respective objects before they return. That way you can have a reference to MetadataImplementor. But I wouldn't really recommend this unless it's really needed, because the APIs might change over time.
On the other hand, if you don't mind building a MetaDataImplemetor from SessionFactory, the following code will help you:
EntityManagerFactoryImpl emf=(EntityManagerFactoryImpl)lcemfb.getNativeEntityManagerFactory();
SessionFactoryImpl sf=emf.getSessionFactory();
StandardServiceRegistry serviceRegistry = sf.getSessionFactoryOptions().getServiceRegistry();
MetadataSources metadataSources = new MetadataSources(new BootstrapServiceRegistryBuilder().build());
Metadata metadata = metadataSources.buildMetadata(serviceRegistry);
SchemaUpdate update=new SchemaUpdate(serviceRegistry,metadata); //To create SchemaUpdate
// You can either create SchemaExport from the above details, or you can get the existing one as follows:
try {
Field field = SessionFactoryImpl.class.getDeclaredField("schemaExport");
field.setAccessible(true);
SchemaExport schemaExport = (SchemaExport) field.get(serviceRegistry);
} catch (NoSuchFieldException | SecurityException | IllegalArgumentException | IllegalAccessException e) {
e.printStackTrace();
}

Take a look on this one:
public class EntityMetaData implements SessionFactoryBuilderFactory {
private static final ThreadLocal<MetadataImplementor> meta = new ThreadLocal<>();
#Override
public SessionFactoryBuilder getSessionFactoryBuilder(MetadataImplementor metadata, SessionFactoryBuilderImplementor defaultBuilder) {
meta.set(metadata);
return defaultBuilder;
}
public static MetadataImplementor getMeta() {
return meta.get();
}
}
Take a look on This Thread which seems to answer your needs

Well, my go to on this:
public class SchemaTranslator {
public static void main(String[] args) throws Exception {
new SchemaTranslator().run();
}
private void run() throws Exception {
String packageName[] = { "model"};
generate(packageName);
}
private List<Class<?>> getClasses(String packageName) throws Exception {
File directory = null;
try {
ClassLoader cld = getClassLoader();
URL resource = getResource(packageName, cld);
directory = new File(resource.getFile());
} catch (NullPointerException ex) {
throw new ClassNotFoundException(packageName + " (" + directory + ") does not appear to be a valid package");
}
return collectClasses(packageName, directory);
}
private ClassLoader getClassLoader() throws ClassNotFoundException {
ClassLoader cld = Thread.currentThread().getContextClassLoader();
if (cld == null) {
throw new ClassNotFoundException("Can't get class loader.");
}
return cld;
}
private URL getResource(String packageName, ClassLoader cld) throws ClassNotFoundException {
String path = packageName.replace('.', '/');
URL resource = cld.getResource(path);
if (resource == null) {
throw new ClassNotFoundException("No resource for " + path);
}
return resource;
}
private List<Class<?>> collectClasses(String packageName, File directory) throws ClassNotFoundException {
List<Class<?>> classes = new ArrayList<>();
if (directory.exists()) {
String[] files = directory.list();
for (String file : files) {
if (file.endsWith(".class")) {
// removes the .class extension
classes.add(Class.forName(packageName + '.' + file.substring(0, file.length() - 6)));
}
}
} else {
throw new ClassNotFoundException(packageName + " is not a valid package");
}
return classes;
}
private void generate(String[] packagesName) throws Exception {
Map<String, String> settings = new HashMap<String, String>();
settings.put("hibernate.hbm2ddl.auto", "drop-create");
settings.put("hibernate.dialect", "org.hibernate.dialect.PostgreSQL94Dialect");
MetadataSources metadata = new MetadataSources(
new StandardServiceRegistryBuilder()
.applySettings(settings)
.build());
for (String packageName : packagesName) {
System.out.println("packageName: " + packageName);
for (Class<?> clazz : getClasses(packageName)) {
System.out.println("Class: " + clazz);
metadata.addAnnotatedClass(clazz);
}
}
SchemaExport export = new SchemaExport(
(MetadataImplementor) metadata.buildMetadata()
);
export.setDelimiter(";");
export.setOutputFile("db-schema.sql");
export.setFormat(true);
export.execute(true, false, false, false);
}
}

How to render freemarker templates that have a symlink in their path?

I am trying to use FreeMarker to render some templates that come from a CMS path that happens to include a symbolic link (under Linux). Our CMS code handles the path to the template so, for example, this path:
/var/cms/live/display/main.html
really points to:
/var/cms/trunk/127/display/main.html
/var/cms/live is the base-directory while /display/main.html is the path.
In my case, live is a symbolic link -- in this case to trunk/127. FYI: the trunk is our SVN branch. When our CMS system downloads a new release of CMS files as (for example) trunk-128.zip, it unpacks it into trunk/128 and then changes the symlink (atomically) to trunk/128. Great.
The problem is that FreeMarker seems to have cached the trunk/127 path. It doesn't recognize that the file /var/cms/live/display/main.html has been updated and if the trunk/127 tree is removed, it generates a 500 error.
500 Unable to load template: /display/main.html
How can I get FreeMarker to cache the proper path?

The problem turned out to be with FreeMarker's FileTemplateLoader class. It does a baseDir.getCanonicalFile(...) call on the base-directory passed into the constructor. When our application booted, the base directory /var/cms/live gets resolved into the real path /var/cms/trunk/127/ by getCanonicalFile(...) so any future changes to the symlink are ignored.
It does this in the constructor, so we were forced to create our own LocalFileTemplateLoader which is listed below.
It is just a basic spring loaded implementation of TemplateLoader. Then when we are building our FreeMarker Configuration we set the template loader:
Configuration config = new Configuration();
LocalTemplateLoader loader = new LocalTemplateLoader();
// this is designed for spring
loader.setBaseDir("/var/cms/live");
config.setTemplateLoader(loader);
...
Here is our LocalFileTemplateLoader code. Full class on pastebin:
public class LocalFileTemplateLoader implements TemplateLoader {
public File baseDir;
#Override
public Object findTemplateSource(String name) {
File source = new File(baseDir, name);
if (source.isFile()) {
return source;
} else {
return null;
}
}
#Override
public long getLastModified(Object templateSource) {
if (templateSource instanceof File) {
return new Long(((File) templateSource).lastModified());
} else {
throw new IllegalArgumentException("templateSource is an unknown type: " + templateSource.getClass());
}
}
#Override
public Reader getReader(Object templateSource, String encoding) throws IOException {
if (templateSource instanceof File) {
return new InputStreamReader(new FileInputStream((File) templateSource), encoding);
} else {
throw new IllegalArgumentException("templateSource is an unknown type: " + templateSource.getClass());
}
}
#Override
public void closeTemplateSource(Object templateSource) {
// noop
}
#Required
public void setBaseDir(File baseDir) {
this.baseDir = baseDir;
// it may not exist yet because CMS is going to download and create it
}
}

Spring 3.1 WebApplicationInitializer & Embedded Jetty 8 AnnotationConfiguration

I'm trying to create a simple webapp without any XML configuration using Spring 3.1 and an embedded Jetty 8 server.
However, I'm struggling to get Jetty to recognise my implementaton of the Spring WebApplicationInitializer interface.
Project structure:
src
+- main
+- java
| +- JettyServer.java
| +- Initializer.java
|
+- webapp
+- web.xml (objective is to remove this - see below).
The Initializer class above is a simple implementation of WebApplicationInitializer:
import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import org.springframework.web.WebApplicationInitializer;
public class Initializer implements WebApplicationInitializer {
#Override
public void onStartup(ServletContext servletContext) throws ServletException {
System.out.println("onStartup");
}
}
Likewise JettyServer is a simple implementation of an embedded Jetty server:
import org.eclipse.jetty.annotations.AnnotationConfiguration;
import org.eclipse.jetty.server.Server;
import org.eclipse.jetty.webapp.Configuration;
import org.eclipse.jetty.webapp.WebAppContext;
public class JettyServer {
public static void main(String[] args) throws Exception {
Server server = new Server(8080);
WebAppContext webAppContext = new WebAppContext();
webAppContext.setResourceBase("src/main/webapp");
webAppContext.setContextPath("/");
webAppContext.setConfigurations(new Configuration[] { new AnnotationConfiguration() });
webAppContext.setParentLoaderPriority(true);
server.setHandler(webAppContext);
server.start();
server.join();
}
}
My understanding is that on startup Jetty will use AnnotationConfiguration to scan for
annotated implementations of ServletContainerInitializer; it should find Initializer and wire it in...
However, when I start the Jetty server (from within Eclipse) I see the following on the command-line:
2012-11-04 16:59:04.552:INFO:oejs.Server:jetty-8.1.7.v20120910
2012-11-04 16:59:05.046:INFO:/:No Spring WebApplicationInitializer types detected on classpath
2012-11-04 16:59:05.046:INFO:oejsh.ContextHandler:started o.e.j.w.WebAppContext{/,file:/Users/duncan/Coding/spring-mvc-embedded-jetty-test/src/main/webapp/}
2012-11-04 16:59:05.117:INFO:oejs.AbstractConnector:Started SelectChannelConnector#0.0.0.0:8080
The important bit is this:
No Spring WebApplicationInitializer types detected on classpath
Note that src/main/java is defined as a source folder in Eclipse, so should be on the classpath. Also note that the Dynamic Web Module Facet is set to 3.0.
I'm sure there's a simple explanation, but I'm struggling to see the wood for the trees! I suspect the key is with the following line:
...
webAppContext.setResourceBase("src/main/webapp");
...
This makes sense with a 2.5 servlet using web.xml (see below), but what should it be when using AnnotationConfiguration?
NB: Everything fires up correctly if I change the Configurations to the following:
...
webAppContext.setConfigurations(new Configuration[] { new WebXmlConfiguration() });
...
In this case it finds the web.xml under src/main/webapp and uses it to wire the servlet using DispatcherServlet and AnnotationConfigWebApplicationContext in the usual way (completely bypassing the WebApplicationInitializer implementation above).
This feels very much like a classpath problem, but I'm struggling to understand quite how Jetty associates itself with implementations of WebApplicationInitializer - any suggestions would be most appreciated!
For info, I'm using the following:
Spring 3.1.1
Jetty 8.1.7
STS 3.1.0

The problem is that Jetty's AnnotationConfiguration class does not scan non-jar resources on the classpath (except under WEB-INF/classes).
It finds my WebApplicationInitializer's if I register a subclass of AnnotationConfiguration which overrides configure(WebAppContext) to scan the host classpath in addition to the container and web-inf locations.
Most of the sub-class is (sadly) copy-paste from the parent. It includes:
an extra parse call (parseHostClassPath) at the end of the configure method;
the parseHostClassPath method which is largely copy-paste from
AnnotationConfiguration's parseWebInfClasses;
the getHostClassPathResource method which grabs the first non-jar URL
from the classloader (which, for me at least, is the file url to my
classpath in eclipse).
I am using slightly different versions of Jetty (8.1.7.v20120910) and Spring (3.1.2_RELEASE), but I imagine the same solution will work.
Edit: I created a working sample project in github with some modifications (the code below works fine from Eclipse but not when running in a shaded jar) - https://github.com/steveliles/jetty-embedded-spring-mvc-noxml
In the OP's JettyServer class the necessary change would replace line 15 with:
webAppContext.setConfigurations (new Configuration []
{
new AnnotationConfiguration()
{
#Override
public void configure(WebAppContext context) throws Exception
{
boolean metadataComplete = context.getMetaData().isMetaDataComplete();
context.addDecorator(new AnnotationDecorator(context));
AnnotationParser parser = null;
if (!metadataComplete)
{
if (context.getServletContext().getEffectiveMajorVersion() >= 3 || context.isConfigurationDiscovered())
{
parser = createAnnotationParser();
parser.registerAnnotationHandler("javax.servlet.annotation.WebServlet", new WebServletAnnotationHandler(context));
parser.registerAnnotationHandler("javax.servlet.annotation.WebFilter", new WebFilterAnnotationHandler(context));
parser.registerAnnotationHandler("javax.servlet.annotation.WebListener", new WebListenerAnnotationHandler(context));
}
}
List<ServletContainerInitializer> nonExcludedInitializers = getNonExcludedInitializers(context);
parser = registerServletContainerInitializerAnnotationHandlers(context, parser, nonExcludedInitializers);
if (parser != null)
{
parseContainerPath(context, parser);
parseWebInfClasses(context, parser);
parseWebInfLib (context, parser);
parseHostClassPath(context, parser);
}
}
private void parseHostClassPath(final WebAppContext context, AnnotationParser parser) throws Exception
{
clearAnnotationList(parser.getAnnotationHandlers());
Resource resource = getHostClassPathResource(getClass().getClassLoader());
if (resource == null)
return;
parser.parse(resource, new ClassNameResolver()
{
public boolean isExcluded (String name)
{
if (context.isSystemClass(name)) return true;
if (context.isServerClass(name)) return false;
return false;
}
public boolean shouldOverride (String name)
{
//looking at webapp classpath, found already-parsed class of same name - did it come from system or duplicate in webapp?
if (context.isParentLoaderPriority())
return false;
return true;
}
});
//TODO - where to set the annotations discovered from WEB-INF/classes?
List<DiscoveredAnnotation> annotations = new ArrayList<DiscoveredAnnotation>();
gatherAnnotations(annotations, parser.getAnnotationHandlers());
context.getMetaData().addDiscoveredAnnotations (annotations);
}
private Resource getHostClassPathResource(ClassLoader loader) throws IOException
{
if (loader instanceof URLClassLoader)
{
URL[] urls = ((URLClassLoader)loader).getURLs();
for (URL url : urls)
if (url.getProtocol().startsWith("file"))
return Resource.newResource(url);
}
return null;
}
},
});
Update: Jetty 8.1.8 introduces internal changes that are incompatible with the code above. For 8.1.8 the following seems to work:
webAppContext.setConfigurations (new Configuration []
{
// This is necessary because Jetty out-of-the-box does not scan
// the classpath of your project in Eclipse, so it doesn't find
// your WebAppInitializer.
new AnnotationConfiguration()
{
#Override
public void configure(WebAppContext context) throws Exception {
boolean metadataComplete = context.getMetaData().isMetaDataComplete();
context.addDecorator(new AnnotationDecorator(context));
//Even if metadata is complete, we still need to scan for ServletContainerInitializers - if there are any
AnnotationParser parser = null;
if (!metadataComplete)
{
//If metadata isn't complete, if this is a servlet 3 webapp or isConfigDiscovered is true, we need to search for annotations
if (context.getServletContext().getEffectiveMajorVersion() >= 3 || context.isConfigurationDiscovered())
{
_discoverableAnnotationHandlers.add(new WebServletAnnotationHandler(context));
_discoverableAnnotationHandlers.add(new WebFilterAnnotationHandler(context));
_discoverableAnnotationHandlers.add(new WebListenerAnnotationHandler(context));
}
}
//Regardless of metadata, if there are any ServletContainerInitializers with #HandlesTypes, then we need to scan all the
//classes so we can call their onStartup() methods correctly
createServletContainerInitializerAnnotationHandlers(context, getNonExcludedInitializers(context));
if (!_discoverableAnnotationHandlers.isEmpty() || _classInheritanceHandler != null || !_containerInitializerAnnotationHandlers.isEmpty())
{
parser = createAnnotationParser();
parse(context, parser);
for (DiscoverableAnnotationHandler h:_discoverableAnnotationHandlers)
context.getMetaData().addDiscoveredAnnotations(((AbstractDiscoverableAnnotationHandler)h).getAnnotationList());
}
}
private void parse(final WebAppContext context, AnnotationParser parser) throws Exception
{
List<Resource> _resources = getResources(getClass().getClassLoader());
for (Resource _resource : _resources)
{
if (_resource == null)
return;
parser.clearHandlers();
for (DiscoverableAnnotationHandler h:_discoverableAnnotationHandlers)
{
if (h instanceof AbstractDiscoverableAnnotationHandler)
((AbstractDiscoverableAnnotationHandler)h).setResource(null); //
}
parser.registerHandlers(_discoverableAnnotationHandlers);
parser.registerHandler(_classInheritanceHandler);
parser.registerHandlers(_containerInitializerAnnotationHandlers);
parser.parse(_resource,
new ClassNameResolver()
{
public boolean isExcluded (String name)
{
if (context.isSystemClass(name)) return true;
if (context.isServerClass(name)) return false;
return false;
}
public boolean shouldOverride (String name)
{
//looking at webapp classpath, found already-parsed class of same name - did it come from system or duplicate in webapp?
if (context.isParentLoaderPriority())
return false;
return true;
}
});
}
}
private List<Resource> getResources(ClassLoader aLoader) throws IOException
{
if (aLoader instanceof URLClassLoader)
{
List<Resource> _result = new ArrayList<Resource>();
URL[] _urls = ((URLClassLoader)aLoader).getURLs();
for (URL _url : _urls)
_result.add(Resource.newResource(_url));
return _result;
}
return Collections.emptyList();
}
}
});

I was able to resolve in an easier but more limited way by just providing explicitly to the AnnotationConfiguration the implementation class (MyWebApplicationInitializerImpl in this example) that I want to be loaded like this:
webAppContext.setConfigurations(new Configuration[] {
new WebXmlConfiguration(),
new AnnotationConfiguration() {
#Override
public void preConfigure(WebAppContext context) throws Exception {
MultiMap<String> map = new MultiMap<String>();
map.add(WebApplicationInitializer.class.getName(), MyWebApplicationInitializerImpl.class.getName());
context.setAttribute(CLASS_INHERITANCE_MAP, map);
_classInheritanceHandler = new ClassInheritanceHandler(map);
}
}
});

Jetty 9.0.1 contains an enhancement which allows for scanning of annotations of non-jar resources (ie classes) on the container classpath. See comment #5 on the following issue for how to use it:
https://bugs.eclipse.org/bugs/show_bug.cgi?id=404176#c5
Jan

The code below did the trick in my maven project:
public static void main(String[] args) throws Exception {
Server server = new Server();
ServerConnector scc = new ServerConnector(server);
scc.setPort(Integer.parseInt(System.getProperty("jetty.port", "8080")));
server.setConnectors(new Connector[] { scc });
WebAppContext context = new WebAppContext();
context.setServer(server);
context.setContextPath("/");
context.setWar("src/main/webapp");
context.getMetaData().addContainerResource(new FileResource(new File("./target/classes").toURI()));
context.setConfigurations(new Configuration[]{
new WebXmlConfiguration(),
new AnnotationConfiguration()
});
server.setHandler(context);
try {
System.out.println(">>> STARTING EMBEDDED JETTY SERVER, PRESS ANY KEY TO STOP");
System.out.println(String.format(">>> open http://localhost:%s/", scc.getPort()));
server.start();
while (System.in.available() == 0) {
Thread.sleep(5000);
}
server.stop();
server.join();
} catch (Throwable t) {
t.printStackTrace();
System.exit(100);
}
}

Based on my testing and this thread http://forum.springsource.org/showthread.php?127152-WebApplicationInitializer-not-loaded-with-embedded-Jetty I don't think it works at the moment. If you look in AnnotationConfiguration.configure:
parseContainerPath(context, parser);
// snip comment
parseWebInfClasses(context, parser);
parseWebInfLib (context, parser);
it seems coupled to a war-like deployment rather than embedded.
Here is an example using Spring MVC and embedded Jetty that might be more useful:
http://www.jamesward.com/2012/08/13/containerless-spring-mvc
It creates the Spring servlet directly rather then relying on annotations.

To those experiencing this lately, it appears this gets around the issue:
#Component
public class Initializer implements WebApplicationInitializer {
private ServletContext servletContext;
#Autowired
public WebInitializer(ServletContext servletContext) {
this.servletContext = servletContext;
}
#PostConstruct
public void onStartup() throws ServletException {
onStartup(servletContext);
}
public void onStartup(ServletContext servletContext) throws ServletException {
System.out.println("onStartup");
}
}

To make it work on Jetty 9 set attribute AnnotationConfiguration.CLASS_INHERITANCE_MAP on WebAppContext
webAppContext.setAttribute(AnnotationConfiguration.CLASS_INHERITANCE_MAP, createClassMap());
And here is how to create this map:
private ClassInheritanceMap createClassMap() {
ClassInheritanceMap classMap = new ClassInheritanceMap();
ConcurrentHashSet<String> impl = new ConcurrentHashSet<>();
impl.add(MyWebAppInitializer.class.getName());
classMap.put(WebApplicationInitializer.class.getName(), impl);
return classMap;
}
I placed that solution on gitHub

What about just setting the context attribute that tells the scanner which things belong on the container classpath that need to be scanned?
context attribute:
org.eclipse.jetty.server.webapp.ContainerIncludeJarPattern
./servlet-api-[^/].jar$
It is designed to be used with jar names, but you could just match everything.
You'd need to use the WebInfConfiguration as well as the AnnotationConfiguration classes.
cheers
Jan

In our case these lines helped in Jetty startup code:
ClassList cl = Configuration.ClassList.setServerDefault(server);
cl.addBefore("org.eclipse.jetty.webapp.JettyWebXmlConfiguration", "org.eclipse.jetty.annotations.AnnotationConfiguration");

Jetty 9 version of "magomarcelo" answer:
context.setConfigurations(
new org.eclipse.jetty.webapp.Configuration[] { new WebXmlConfiguration(), new AnnotationConfiguration() {
#Override
public void preConfigure(WebAppContext context) throws Exception {
final ClassInheritanceMap map = new ClassInheritanceMap();
final ConcurrentHashSet<String> set = new ConcurrentHashSet<>();
set.add(MyWebAppInitializer.class.getName());
map.put(WebApplicationInitializer.class.getName(), set);
context.setAttribute(CLASS_INHERITANCE_MAP, map);
_classInheritanceHandler = new ClassInheritanceHandler(map);
}
} });

For Jetty 9, if you have webjars, the solution provided does not work straight away as those Jars need to be on the classpath and the JAR contents need to be available as resources for your webapp. So, for that to work together with webjars, the config would have to be:
context.setExtraClasspath(pathsToWebJarsCommaSeparated);
context.setAttribute(WebInfConfiguration.WEBINF_JAR_PATTERN, ".*\\.jar$");
context.setAttribute(WebInfConfiguration.CONTAINER_JAR_PATTERN, ".*\\.jar$");
context.setConfigurations(
new org.eclipse.jetty.webapp.Configuration[] {
new WebInfConfiguration(), new MetaInfConfiguration(),
new AnnotationConfiguration() {
#Override
public void preConfigure(WebAppContext context) throws Exception {
final ClassInheritanceMap map = new ClassInheritanceMap();
final ConcurrentHashSet<String> set = new ConcurrentHashSet<>();
set.add(MyWebAppInitializer.class.getName());
map.put(WebApplicationInitializer.class.getName(), set);
context.setAttribute(CLASS_INHERITANCE_MAP, map);
_classInheritanceHandler = new ClassInheritanceHandler(map);
}
} });
The order here is important (WebInfConfiguration has to come before MetaInf).

Solution that worked for me and does not involve scanning, but uses WebApplicationInitializer class that you provide. Jetty version: 9.2.20
public class Main {
public static void main(String... args) throws Exception {
Properties properties = new Properties();
InputStream stream = Main.class.getResourceAsStream("/WEB-INF/application.properties");
properties.load(stream);
stream.close();
PropertyConfigurator.configure(properties);
WebAppContext webAppContext = new WebAppContext();
webAppContext.setResourceBase("resource");
webAppContext.setContextPath(properties.getProperty("base.url"));
webAppContext.setConfigurations(new Configuration[] {
new WebXmlConfiguration(),
new AnnotationConfiguration() {
#Override
public void preConfigure(WebAppContext context) {
ClassInheritanceMap map = new ClassInheritanceMap();
map.put(WebApplicationInitializer.class.getName(), new ConcurrentHashSet<String>() {{
add(WebInitializer.class.getName());
add(SecurityWebInitializer.class.getName());
}});
context.setAttribute(CLASS_INHERITANCE_MAP, map);
_classInheritanceHandler = new ClassInheritanceHandler(map);
}
}
});
Server server = new Server(Integer.parseInt(properties.getProperty("base.port")));
server.setHandler(webAppContext);
server.start();
server.join();
}
}
The source (in russian) of this code snippet is here: https://habrahabr.ru/post/255773/

did a simple maven project to demonstrate how it can be done cleanly.
public class Console {
public static void main(String[] args) {
try {
Server server = new Server(8080);
//Set a handler to handle requests.
server.setHandler(getWebAppContext());
//starts to listen at 0.0.0.0:8080
server.start();
server.join();
} catch (Exception e) {
log.error("server exited with exception", e);
}
}
private static WebAppContext getWebAppContext() {
final WebAppContext webAppContext = new WebAppContext();
//route all requests via this web-app.
webAppContext.setContextPath("/");
/*
* point to location where the jar into which this class gets packaged into resides.
* this could very well be the target directory in a maven development build.
*/
webAppContext.setResourceBase("directory_where_the_application_jar_exists");
//no web inf for us - so let the scanning know about location of our libraries / classes.
webAppContext.getMetaData().setWebInfClassesDirs(Arrays.asList(webAppContext.getBaseResource()));
//Scan for annotations (servlet 3+)
final AnnotationConfiguration configuration = new AnnotationConfiguration();
webAppContext.setConfigurations(new Configuration[]{configuration});
return webAppContext;
}
}
and that's all - the spring WebApplicationInitializer that you use will get detected without explicitly letting jetty server know about the existence of such an app initializer.